1. Field of the Invention
This invention relates to electronic engine controls for operation of an internal combustion engine.
2. Prior Art
It is known to control the air fuel ratio of an internal combustion engine using various air fuel control strategies. Factors such as ambient air pressure, mass air flow, and intake air temperature have been used in the process of controlling air fuel ratio for an internal combustion engine.
Further, the proper operation of a catalyst processing the exhaust gas from an internal combustion engine depends, in part, upon the air fuel ratio supplied to the engine. Associated with the downstream flow of exhaust gas and the catalyst it is known to use an exhaust gas oxygen sensor to sense the concentration of oxygen in the exhaust gas. Knowledge of the exhaust gas oxygen concentration can be used to control the air fuel ratio.
Previous approaches have used exhaust gas temperature prediction strategy based upon the catalyst midbed temperature in the exhaust gas.
It would be desirable to improve control of the air fuel ratio in an engine by better taking into account the operating conditions of the engine, including exhaust gas oxygen sensor temperature.